<?php

# KCAPTCHA PROJECT VERSION 1.2.6
# Automatic test to tell computers and humans apart
# Copyright by Kruglov Sergei,2006,2007,2008
# www.captcha.ru,www.kruglov.ru
# System requirements: PHP 4.0.6+w/ GD
# KCAPTCHA is a free software.You can freely use it for building own site or software.
# If you use this software as a part of own sofware,you must leave copyright notices intact or add KCAPTCHA copyright notices to own.
# As a default configuration,KCAPTCHA has a small credits text at bottom of CAPTCHA image.
# You can remove it,but I would be pleased if you left it.;)
# See kcaptcha_config.php for customization
class KCAPTCHA{
function KCAPTCHA(){
require(dirname(__FILE__).'/kcaptcha_config.php');
$fonts=array();
$fontsdir_absolute=dirname(__FILE__).'/'.$fontsdir;
if ($handle = opendir($fontsdir_absolute)) {
while (false !== ($file = readdir($handle))) {
if (preg_match('/\.png$/i',$file)) {
$fonts[]=$fontsdir_absolute.'/'.$file;
}
}
closedir($handle);
}
$alphabet_length=strlen($alphabet);
do{
while(true){
$this->keystring='';
for($i=0;$i<$length;$i++){
$this->keystring.=$allowed_symbols{mt_rand(0,strlen($allowed_symbols)-1)};
}
if(!preg_match('/cp|cb|ck|c6|c9|rn|rm|mm|co|do|cl|db|qp|qb|dp|ww/',$this->keystring)) break;
}
$font_file=$fonts[mt_rand(0,count($fonts)-1)];
$font=imagecreatefrompng($font_file);
imagealphablending($font,true);
$fontfile_width=imagesx($font);
$fontfile_height=imagesy($font)-1;
$font_metrics=array();
$symbol=0;
$reading_symbol=false;
for($i=0;$i<$fontfile_width &&$symbol<$alphabet_length;$i++){
$transparent = (imagecolorat($font,$i,0) >>24) == 127;
if(!$reading_symbol &&!$transparent){
$font_metrics[$alphabet{$symbol}]=array('start'=>$i);
$reading_symbol=true;
continue;
}
if($reading_symbol &&$transparent){
$font_metrics[$alphabet{$symbol}]['end']=$i;
$reading_symbol=false;
$symbol++;
continue;
}
}
$img=imagecreatetruecolor($width,$height);
imagealphablending($img,true);
$white=imagecolorallocate($img,255,255,255);
$black=imagecolorallocate($img,0,0,0);
imagefilledrectangle($img,0,0,$width-1,$height-1,$white);
$x=1;
for($i=0;$i<$length;$i++){
$m=$font_metrics[$this->keystring{$i}];
$y=mt_rand(-$fluctuation_amplitude,$fluctuation_amplitude)+($height-$fontfile_height)/2+2;
if($no_spaces){
$shift=0;
if($i>0){
$shift=10000;
for($sy=7;$sy<$fontfile_height-20;$sy+=1){
for($sx=$m['start']-1;$sx<$m['end'];$sx+=1){
$rgb=imagecolorat($font,$sx,$sy);
$opacity=$rgb>>24;
if($opacity<127){
$left=$sx-$m['start']+$x;
$py=$sy+$y;
if($py>$height) break;
for($px=min($left,$width-1);$px>$left-12 &&$px>=0;$px-=1){
$color=imagecolorat($img,$px,$py) &0xff;
if($color+$opacity<190){
if($shift>$left-$px){
$shift=$left-$px;
}
break;
}
}
break;
}
}
}
if($shift==10000){
$shift=mt_rand(4,6);
}
}
}else{
$shift=1;
}
imagecopy($img,$font,$x-$shift,$y,$m['start'],1,$m['end']-$m['start'],$fontfile_height);
$x+=$m['end']-$m['start']-$shift;
}
}while($x>=$width-10);
$center=$x/2;
$show_credits = 0;
$img2=imagecreatetruecolor($width,$height+($show_credits?12:0));
$foreground=imagecolorallocate($img2,$foreground_color[0],$foreground_color[1],$foreground_color[2]);
$background=imagecolorallocate($img2,$background_color[0],$background_color[1],$background_color[2]);
imagefilledrectangle($img2,0,0,$width-1,$height-1,$background);
imagefilledrectangle($img2,0,$height,$width-1,$height+12,$foreground);
$credits=empty($credits)?$_SERVER['HTTP_HOST']:$credits;
imagestring($img2,2,$width/2-imagefontwidth(2)*strlen($credits)/2,$height-2,$credits,$background);
$rand1=mt_rand(750000,1200000)/10000000;
$rand2=mt_rand(750000,1200000)/10000000;
$rand3=mt_rand(750000,1200000)/10000000;
$rand4=mt_rand(750000,1200000)/10000000;
$rand5=mt_rand(0,31415926)/10000000;
$rand6=mt_rand(0,31415926)/10000000;
$rand7=mt_rand(0,31415926)/10000000;
$rand8=mt_rand(0,31415926)/10000000;
$rand9=mt_rand(330,420)/110;
$rand10=mt_rand(330,450)/110;
for($x=0;$x<$width;$x++){
for($y=0;$y<$height;$y++){
$sx=$x+(sin($x*$rand1+$rand5)+sin($y*$rand3+$rand6))*$rand9-$width/2+$center+1;
$sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*$rand10;
if($sx<0 ||$sy<0 ||$sx>=$width-1 ||$sy>=$height-1){
continue;
}else{
$color=imagecolorat($img,$sx,$sy) &0xFF;
$color_x=imagecolorat($img,$sx+1,$sy) &0xFF;
$color_y=imagecolorat($img,$sx,$sy+1) &0xFF;
$color_xy=imagecolorat($img,$sx+1,$sy+1) &0xFF;
}
if($color==255 &&$color_x==255 &&$color_y==255 &&$color_xy==255){
continue;
}else if($color==0 &&$color_x==0 &&$color_y==0 &&$color_xy==0){
$newred=$foreground_color[0];
$newgreen=$foreground_color[1];
$newblue=$foreground_color[2];
}else{
$frsx=$sx-floor($sx);
$frsy=$sy-floor($sy);
$frsx1=1-$frsx;
$frsy1=1-$frsy;
$newcolor=(
$color*$frsx1*$frsy1+
$color_x*$frsx*$frsy1+
$color_y*$frsx1*$frsy+
$color_xy*$frsx*$frsy);
if($newcolor>255) $newcolor=255;
$newcolor=$newcolor/255;
$newcolor0=1-$newcolor;
$newred=$newcolor0*$foreground_color[0]+$newcolor*$background_color[0];
$newgreen=$newcolor0*$foreground_color[1]+$newcolor*$background_color[1];
$newblue=$newcolor0*$foreground_color[2]+$newcolor*$background_color[2];
}
imagesetpixel($img2,$x,$y,imagecolorallocate($img2,$newred,$newgreen,$newblue));
}
}
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
header('Cache-Control: no-store, no-cache, must-revalidate');
header('Cache-Control: post-check=0, pre-check=0',FALSE);
header('Pragma: no-cache');
if(function_exists("imagejpeg")){
header("Content-Type: image/jpeg");
imagejpeg($img2,null,$jpeg_quality);
}else if(function_exists("imagegif")){
header("Content-Type: image/gif");
imagegif($img2);
}else if(function_exists("imagepng")){
header("Content-Type: image/x-png");
imagepng($img2);
}
}
function getKeyString(){
return $this->keystring;
}
}
?>